Safety evaluation of longan seed extract: Acute and repeated oral administration

Longan seed extract (LSE) contains high levels of beneficial polyphenolic compounds. The present study evaluated acute and repeated dose (4 and 13 weeks) toxicological effects of aqueous extract of longan seed to ensure the safety of utilization of this extract. Our study revealed that all treated animals survived through the whole experimental periods without adverse effects observed in either sex of animals after acute and repeated dose (4 and 13 weeks) oral administration of LSE. Likewise, growth pattern (body weights, food consumption, and relative organ weights), hematology analysis, and clinical biochemistry analysis in all LSE-treated animals were in normal physiological ranges. Moreover, histopathological finding of LSE-treated animals in repeated dose studies demonstrated no obvious alterations. Although the significant increment in food consumption of female rats (100 mg/kg, Week 4) and % eosinophil of male rats (400 mg/kg), and decrement in food consumption of male rats (250 mg/kg, Week 3 and 9) were observed, these alterations were not dose- and time-response relationships. Therefore, we concluded that acute and repeated dose (4 and 13 weeks) oral administration of LSE has no significant toxicological effects;hence it may be safe to use with caution pending its chronic toxicity study and/or clinical trial.